On the Passive Force Closure Set of Planar Grasps and Fixtures

13 years 2 months ago

Download www.bgu.ac.il

This paper considers grasps and ﬁxtures whose contacts react according to force-displacement laws consistent with friction constrains at the contacts. The passive force closure set of such grasps and ﬁxtures is the set of external wrenches (forces and torques) that can act on the grasped object and be stably balanced by the contacts. An external wrench belongs to this set if it induces a feasible equilibrium whose basin of attraction contains the initial unperturbed grasp conﬁguration. The paper focuses on planar grasps and ﬁxtures having sharp-tipped ﬁngers or ﬁxels that satisfy linear force-displacement laws. Using Morse Theory, the paper characterizes the number and stability type of the k-contact equilibria induced by a given external wrench. Based on this analysis, the paper provides closed-form expressions for the passive force closure set of k-contact grasps and ﬁxtures. Computation of the allowed external wrenches is illustrated with examples. Finally, the paper d...

Amir Shapiro, Elon Rimon, Shraga Shoval

Real-time Traffic